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d26c3321 WL |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Provide a pstore intermediate backend, organized into kernel memory | |
4 | * allocated zones that are then mapped and flushed into a single | |
5 | * contiguous region on a storage backend of some kind (block, mtd, etc). | |
6 | */ | |
7 | ||
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/mount.h> | |
14 | #include <linux/printk.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/pstore_zone.h> | |
17 | #include <linux/kdev_t.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/namei.h> | |
20 | #include <linux/fcntl.h> | |
21 | #include <linux/uio.h> | |
22 | #include <linux/writeback.h> | |
23 | #include "internal.h" | |
24 | ||
25 | /** | |
26 | * struct psz_head - header of zone to flush to storage | |
27 | * | |
28 | * @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value) | |
29 | * @datalen: length of data in @data | |
0dc06826 | 30 | * @start: offset into @data where the beginning of the stored bytes begin |
d26c3321 WL |
31 | * @data: zone data. |
32 | */ | |
33 | struct psz_buffer { | |
34 | #define PSZ_SIG (0x43474244) /* DBGC */ | |
35 | uint32_t sig; | |
36 | atomic_t datalen; | |
0dc06826 | 37 | atomic_t start; |
d26c3321 WL |
38 | uint8_t data[]; |
39 | }; | |
40 | ||
41 | /** | |
42 | * struct psz_kmsg_header - kmsg dump-specific header to flush to storage | |
43 | * | |
44 | * @magic: magic num for kmsg dump header | |
45 | * @time: kmsg dump trigger time | |
46 | * @compressed: whether conpressed | |
47 | * @counter: kmsg dump counter | |
48 | * @reason: the kmsg dump reason (e.g. oops, panic, etc) | |
49 | * @data: pointer to log data | |
50 | * | |
51 | * This is a sub-header for a kmsg dump, trailing after &psz_buffer. | |
52 | */ | |
53 | struct psz_kmsg_header { | |
54 | #define PSTORE_KMSG_HEADER_MAGIC 0x4dfc3ae5 /* Just a random number */ | |
55 | uint32_t magic; | |
56 | struct timespec64 time; | |
57 | bool compressed; | |
58 | uint32_t counter; | |
59 | enum kmsg_dump_reason reason; | |
60 | uint8_t data[]; | |
61 | }; | |
62 | ||
63 | /** | |
64 | * struct pstore_zone - single stored buffer | |
65 | * | |
66 | * @off: zone offset of storage | |
67 | * @type: front-end type for this zone | |
68 | * @name: front-end name for this zone | |
69 | * @buffer: pointer to data buffer managed by this zone | |
70 | * @oldbuf: pointer to old data buffer | |
71 | * @buffer_size: bytes in @buffer->data | |
72 | * @should_recover: whether this zone should recover from storage | |
73 | * @dirty: whether the data in @buffer dirty | |
74 | * | |
75 | * zone structure in memory. | |
76 | */ | |
77 | struct pstore_zone { | |
78 | loff_t off; | |
79 | const char *name; | |
80 | enum pstore_type_id type; | |
81 | ||
82 | struct psz_buffer *buffer; | |
83 | struct psz_buffer *oldbuf; | |
84 | size_t buffer_size; | |
85 | bool should_recover; | |
86 | atomic_t dirty; | |
87 | }; | |
88 | ||
89 | /** | |
90 | * struct psz_context - all about running state of pstore/zone | |
91 | * | |
92 | * @kpszs: kmsg dump storage zones | |
0dc06826 | 93 | * @ppsz: pmsg storage zone |
d26c3321 WL |
94 | * @kmsg_max_cnt: max count of @kpszs |
95 | * @kmsg_read_cnt: counter of total read kmsg dumps | |
96 | * @kmsg_write_cnt: counter of total kmsg dump writes | |
0dc06826 | 97 | * @pmsg_read_cnt: counter of total read pmsg zone |
d26c3321 WL |
98 | * @oops_counter: counter of oops dumps |
99 | * @panic_counter: counter of panic dumps | |
100 | * @recovered: whether finished recovering data from storage | |
101 | * @on_panic: whether panic is happening | |
102 | * @pstore_zone_info_lock: lock to @pstore_zone_info | |
103 | * @pstore_zone_info: information from backend | |
104 | * @pstore: structure for pstore | |
105 | */ | |
106 | struct psz_context { | |
107 | struct pstore_zone **kpszs; | |
0dc06826 | 108 | struct pstore_zone *ppsz; |
d26c3321 WL |
109 | unsigned int kmsg_max_cnt; |
110 | unsigned int kmsg_read_cnt; | |
111 | unsigned int kmsg_write_cnt; | |
0dc06826 | 112 | unsigned int pmsg_read_cnt; |
d26c3321 WL |
113 | /* |
114 | * These counters should be calculated during recovery. | |
115 | * It records the oops/panic times after crashes rather than boots. | |
116 | */ | |
117 | unsigned int oops_counter; | |
118 | unsigned int panic_counter; | |
119 | atomic_t recovered; | |
120 | atomic_t on_panic; | |
121 | ||
122 | /* | |
123 | * pstore_zone_info_lock protects this entire structure during calls | |
124 | * to register_pstore_zone()/unregister_pstore_zone(). | |
125 | */ | |
126 | struct mutex pstore_zone_info_lock; | |
127 | struct pstore_zone_info *pstore_zone_info; | |
128 | struct pstore_info pstore; | |
129 | }; | |
130 | static struct psz_context pstore_zone_cxt; | |
131 | ||
132 | /** | |
133 | * enum psz_flush_mode - flush mode for psz_zone_write() | |
134 | * | |
135 | * @FLUSH_NONE: do not flush to storage but update data on memory | |
136 | * @FLUSH_PART: just flush part of data including meta data to storage | |
137 | * @FLUSH_META: just flush meta data of zone to storage | |
138 | * @FLUSH_ALL: flush all of zone | |
139 | */ | |
140 | enum psz_flush_mode { | |
141 | FLUSH_NONE = 0, | |
142 | FLUSH_PART, | |
143 | FLUSH_META, | |
144 | FLUSH_ALL, | |
145 | }; | |
146 | ||
147 | static inline int buffer_datalen(struct pstore_zone *zone) | |
148 | { | |
149 | return atomic_read(&zone->buffer->datalen); | |
150 | } | |
151 | ||
0dc06826 WL |
152 | static inline int buffer_start(struct pstore_zone *zone) |
153 | { | |
154 | return atomic_read(&zone->buffer->start); | |
155 | } | |
156 | ||
d26c3321 WL |
157 | static inline bool is_on_panic(void) |
158 | { | |
159 | return atomic_read(&pstore_zone_cxt.on_panic); | |
160 | } | |
161 | ||
0dc06826 | 162 | static ssize_t psz_zone_read_buffer(struct pstore_zone *zone, char *buf, |
d26c3321 WL |
163 | size_t len, unsigned long off) |
164 | { | |
0dc06826 | 165 | if (!buf || !zone || !zone->buffer) |
d26c3321 WL |
166 | return -EINVAL; |
167 | if (off > zone->buffer_size) | |
168 | return -EINVAL; | |
169 | len = min_t(size_t, len, zone->buffer_size - off); | |
170 | memcpy(buf, zone->buffer->data + off, len); | |
171 | return len; | |
172 | } | |
173 | ||
0dc06826 WL |
174 | static int psz_zone_read_oldbuf(struct pstore_zone *zone, char *buf, |
175 | size_t len, unsigned long off) | |
176 | { | |
177 | if (!buf || !zone || !zone->oldbuf) | |
178 | return -EINVAL; | |
179 | if (off > zone->buffer_size) | |
180 | return -EINVAL; | |
181 | len = min_t(size_t, len, zone->buffer_size - off); | |
182 | memcpy(buf, zone->oldbuf->data + off, len); | |
183 | return 0; | |
184 | } | |
185 | ||
d26c3321 WL |
186 | static int psz_zone_write(struct pstore_zone *zone, |
187 | enum psz_flush_mode flush_mode, const char *buf, | |
188 | size_t len, unsigned long off) | |
189 | { | |
190 | struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; | |
191 | ssize_t wcnt = 0; | |
192 | ssize_t (*writeop)(const char *buf, size_t bytes, loff_t pos); | |
193 | size_t wlen; | |
194 | ||
195 | if (off > zone->buffer_size) | |
196 | return -EINVAL; | |
197 | ||
198 | wlen = min_t(size_t, len, zone->buffer_size - off); | |
199 | if (buf && wlen) { | |
200 | memcpy(zone->buffer->data + off, buf, wlen); | |
201 | atomic_set(&zone->buffer->datalen, wlen + off); | |
202 | } | |
203 | ||
204 | /* avoid to damage old records */ | |
205 | if (!is_on_panic() && !atomic_read(&pstore_zone_cxt.recovered)) | |
206 | goto dirty; | |
207 | ||
208 | writeop = is_on_panic() ? info->panic_write : info->write; | |
209 | if (!writeop) | |
210 | goto dirty; | |
211 | ||
212 | switch (flush_mode) { | |
213 | case FLUSH_NONE: | |
214 | if (unlikely(buf && wlen)) | |
215 | goto dirty; | |
216 | return 0; | |
217 | case FLUSH_PART: | |
218 | wcnt = writeop((const char *)zone->buffer->data + off, wlen, | |
219 | zone->off + sizeof(*zone->buffer) + off); | |
220 | if (wcnt != wlen) | |
221 | goto dirty; | |
222 | fallthrough; | |
223 | case FLUSH_META: | |
224 | wlen = sizeof(struct psz_buffer); | |
225 | wcnt = writeop((const char *)zone->buffer, wlen, zone->off); | |
226 | if (wcnt != wlen) | |
227 | goto dirty; | |
228 | break; | |
229 | case FLUSH_ALL: | |
230 | wlen = zone->buffer_size + sizeof(*zone->buffer); | |
231 | wcnt = writeop((const char *)zone->buffer, wlen, zone->off); | |
232 | if (wcnt != wlen) | |
233 | goto dirty; | |
234 | break; | |
235 | } | |
236 | ||
237 | return 0; | |
238 | dirty: | |
239 | atomic_set(&zone->dirty, true); | |
240 | return -EBUSY; | |
241 | } | |
242 | ||
243 | static int psz_flush_dirty_zone(struct pstore_zone *zone) | |
244 | { | |
245 | int ret; | |
246 | ||
247 | if (unlikely(!zone)) | |
248 | return -EINVAL; | |
249 | ||
250 | if (unlikely(!atomic_read(&pstore_zone_cxt.recovered))) | |
251 | return -EBUSY; | |
252 | ||
253 | if (!atomic_xchg(&zone->dirty, false)) | |
254 | return 0; | |
255 | ||
256 | ret = psz_zone_write(zone, FLUSH_ALL, NULL, 0, 0); | |
257 | if (ret) | |
258 | atomic_set(&zone->dirty, true); | |
259 | return ret; | |
260 | } | |
261 | ||
262 | static int psz_flush_dirty_zones(struct pstore_zone **zones, unsigned int cnt) | |
263 | { | |
264 | int i, ret; | |
265 | struct pstore_zone *zone; | |
266 | ||
267 | if (!zones) | |
268 | return -EINVAL; | |
269 | ||
270 | for (i = 0; i < cnt; i++) { | |
271 | zone = zones[i]; | |
272 | if (!zone) | |
273 | return -EINVAL; | |
274 | ret = psz_flush_dirty_zone(zone); | |
275 | if (ret) | |
276 | return ret; | |
277 | } | |
278 | return 0; | |
279 | } | |
280 | ||
281 | static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new) | |
282 | { | |
283 | const char *data = (const char *)old->buffer->data; | |
284 | int ret; | |
285 | ||
286 | ret = psz_zone_write(new, FLUSH_ALL, data, buffer_datalen(old), 0); | |
287 | if (ret) { | |
288 | atomic_set(&new->buffer->datalen, 0); | |
289 | atomic_set(&new->dirty, false); | |
290 | return ret; | |
291 | } | |
292 | atomic_set(&old->buffer->datalen, 0); | |
293 | return 0; | |
294 | } | |
295 | ||
296 | static int psz_kmsg_recover_data(struct psz_context *cxt) | |
297 | { | |
298 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
299 | struct pstore_zone *zone = NULL; | |
300 | struct psz_buffer *buf; | |
301 | unsigned long i; | |
302 | ssize_t rcnt; | |
303 | ||
304 | if (!info->read) | |
305 | return -EINVAL; | |
306 | ||
307 | for (i = 0; i < cxt->kmsg_max_cnt; i++) { | |
308 | zone = cxt->kpszs[i]; | |
309 | if (unlikely(!zone)) | |
310 | return -EINVAL; | |
311 | if (atomic_read(&zone->dirty)) { | |
312 | unsigned int wcnt = cxt->kmsg_write_cnt; | |
313 | struct pstore_zone *new = cxt->kpszs[wcnt]; | |
314 | int ret; | |
315 | ||
316 | ret = psz_move_zone(zone, new); | |
317 | if (ret) { | |
318 | pr_err("move zone from %lu to %d failed\n", | |
319 | i, wcnt); | |
320 | return ret; | |
321 | } | |
322 | cxt->kmsg_write_cnt = (wcnt + 1) % cxt->kmsg_max_cnt; | |
323 | } | |
324 | if (!zone->should_recover) | |
325 | continue; | |
326 | buf = zone->buffer; | |
327 | rcnt = info->read((char *)buf, zone->buffer_size + sizeof(*buf), | |
328 | zone->off); | |
329 | if (rcnt != zone->buffer_size + sizeof(*buf)) | |
330 | return (int)rcnt < 0 ? (int)rcnt : -EIO; | |
331 | } | |
332 | return 0; | |
333 | } | |
334 | ||
335 | static int psz_kmsg_recover_meta(struct psz_context *cxt) | |
336 | { | |
337 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
338 | struct pstore_zone *zone; | |
339 | size_t rcnt, len; | |
340 | struct psz_buffer *buf; | |
341 | struct psz_kmsg_header *hdr; | |
342 | struct timespec64 time = { }; | |
343 | unsigned long i; | |
344 | /* | |
345 | * Recover may on panic, we can't allocate any memory by kmalloc. | |
346 | * So, we use local array instead. | |
347 | */ | |
348 | char buffer_header[sizeof(*buf) + sizeof(*hdr)] = {0}; | |
349 | ||
350 | if (!info->read) | |
351 | return -EINVAL; | |
352 | ||
353 | len = sizeof(*buf) + sizeof(*hdr); | |
354 | buf = (struct psz_buffer *)buffer_header; | |
355 | for (i = 0; i < cxt->kmsg_max_cnt; i++) { | |
356 | zone = cxt->kpszs[i]; | |
357 | if (unlikely(!zone)) | |
358 | return -EINVAL; | |
359 | ||
360 | rcnt = info->read((char *)buf, len, zone->off); | |
361 | if (rcnt != len) { | |
362 | pr_err("read %s with id %lu failed\n", zone->name, i); | |
363 | return (int)rcnt < 0 ? (int)rcnt : -EIO; | |
364 | } | |
365 | ||
366 | if (buf->sig != zone->buffer->sig) { | |
367 | pr_debug("no valid data in kmsg dump zone %lu\n", i); | |
368 | continue; | |
369 | } | |
370 | ||
371 | if (zone->buffer_size < atomic_read(&buf->datalen)) { | |
372 | pr_info("found overtop zone: %s: id %lu, off %lld, size %zu\n", | |
373 | zone->name, i, zone->off, | |
374 | zone->buffer_size); | |
375 | continue; | |
376 | } | |
377 | ||
378 | hdr = (struct psz_kmsg_header *)buf->data; | |
379 | if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) { | |
380 | pr_info("found invalid zone: %s: id %lu, off %lld, size %zu\n", | |
381 | zone->name, i, zone->off, | |
382 | zone->buffer_size); | |
383 | continue; | |
384 | } | |
385 | ||
386 | /* | |
387 | * we get the newest zone, and the next one must be the oldest | |
388 | * or unused zone, because we do write one by one like a circle. | |
389 | */ | |
390 | if (hdr->time.tv_sec >= time.tv_sec) { | |
391 | time.tv_sec = hdr->time.tv_sec; | |
392 | cxt->kmsg_write_cnt = (i + 1) % cxt->kmsg_max_cnt; | |
393 | } | |
394 | ||
395 | if (hdr->reason == KMSG_DUMP_OOPS) | |
396 | cxt->oops_counter = | |
397 | max(cxt->oops_counter, hdr->counter); | |
398 | else if (hdr->reason == KMSG_DUMP_PANIC) | |
399 | cxt->panic_counter = | |
400 | max(cxt->panic_counter, hdr->counter); | |
401 | ||
402 | if (!atomic_read(&buf->datalen)) { | |
403 | pr_debug("found erased zone: %s: id %lu, off %lld, size %zu, datalen %d\n", | |
404 | zone->name, i, zone->off, | |
405 | zone->buffer_size, | |
406 | atomic_read(&buf->datalen)); | |
407 | continue; | |
408 | } | |
409 | ||
410 | if (!is_on_panic()) | |
411 | zone->should_recover = true; | |
412 | pr_debug("found nice zone: %s: id %lu, off %lld, size %zu, datalen %d\n", | |
413 | zone->name, i, zone->off, | |
414 | zone->buffer_size, atomic_read(&buf->datalen)); | |
415 | } | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
420 | static int psz_kmsg_recover(struct psz_context *cxt) | |
421 | { | |
422 | int ret; | |
423 | ||
424 | if (!cxt->kpszs) | |
425 | return 0; | |
426 | ||
427 | ret = psz_kmsg_recover_meta(cxt); | |
428 | if (ret) | |
429 | goto recover_fail; | |
430 | ||
431 | ret = psz_kmsg_recover_data(cxt); | |
432 | if (ret) | |
433 | goto recover_fail; | |
434 | ||
435 | return 0; | |
436 | recover_fail: | |
437 | pr_debug("psz_recover_kmsg failed\n"); | |
438 | return ret; | |
439 | } | |
440 | ||
0dc06826 WL |
441 | static int psz_recover_zone(struct psz_context *cxt, struct pstore_zone *zone) |
442 | { | |
443 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
444 | struct psz_buffer *oldbuf, tmpbuf; | |
445 | int ret = 0; | |
446 | char *buf; | |
447 | ssize_t rcnt, len, start, off; | |
448 | ||
449 | if (!zone || zone->oldbuf) | |
450 | return 0; | |
451 | ||
452 | if (is_on_panic()) { | |
453 | /* save data as much as possible */ | |
454 | psz_flush_dirty_zone(zone); | |
455 | return 0; | |
456 | } | |
457 | ||
458 | if (unlikely(!info->read)) | |
459 | return -EINVAL; | |
460 | ||
461 | len = sizeof(struct psz_buffer); | |
462 | rcnt = info->read((char *)&tmpbuf, len, zone->off); | |
463 | if (rcnt != len) { | |
464 | pr_debug("read zone %s failed\n", zone->name); | |
465 | return (int)rcnt < 0 ? (int)rcnt : -EIO; | |
466 | } | |
467 | ||
468 | if (tmpbuf.sig != zone->buffer->sig) { | |
469 | pr_debug("no valid data in zone %s\n", zone->name); | |
470 | return 0; | |
471 | } | |
472 | ||
473 | if (zone->buffer_size < atomic_read(&tmpbuf.datalen) || | |
474 | zone->buffer_size < atomic_read(&tmpbuf.start)) { | |
475 | pr_info("found overtop zone: %s: off %lld, size %zu\n", | |
476 | zone->name, zone->off, zone->buffer_size); | |
477 | /* just keep going */ | |
478 | return 0; | |
479 | } | |
480 | ||
481 | if (!atomic_read(&tmpbuf.datalen)) { | |
482 | pr_debug("found erased zone: %s: off %lld, size %zu, datalen %d\n", | |
483 | zone->name, zone->off, zone->buffer_size, | |
484 | atomic_read(&tmpbuf.datalen)); | |
485 | return 0; | |
486 | } | |
487 | ||
488 | pr_debug("found nice zone: %s: off %lld, size %zu, datalen %d\n", | |
489 | zone->name, zone->off, zone->buffer_size, | |
490 | atomic_read(&tmpbuf.datalen)); | |
491 | ||
492 | len = atomic_read(&tmpbuf.datalen) + sizeof(*oldbuf); | |
493 | oldbuf = kzalloc(len, GFP_KERNEL); | |
494 | if (!oldbuf) | |
495 | return -ENOMEM; | |
496 | ||
497 | memcpy(oldbuf, &tmpbuf, sizeof(*oldbuf)); | |
498 | buf = (char *)oldbuf + sizeof(*oldbuf); | |
499 | len = atomic_read(&oldbuf->datalen); | |
500 | start = atomic_read(&oldbuf->start); | |
501 | off = zone->off + sizeof(*oldbuf); | |
502 | ||
503 | /* get part of data */ | |
504 | rcnt = info->read(buf, len - start, off + start); | |
505 | if (rcnt != len - start) { | |
506 | pr_err("read zone %s failed\n", zone->name); | |
507 | ret = (int)rcnt < 0 ? (int)rcnt : -EIO; | |
508 | goto free_oldbuf; | |
509 | } | |
510 | ||
511 | /* get the rest of data */ | |
512 | rcnt = info->read(buf + len - start, start, off); | |
513 | if (rcnt != start) { | |
514 | pr_err("read zone %s failed\n", zone->name); | |
515 | ret = (int)rcnt < 0 ? (int)rcnt : -EIO; | |
516 | goto free_oldbuf; | |
517 | } | |
518 | ||
519 | zone->oldbuf = oldbuf; | |
520 | psz_flush_dirty_zone(zone); | |
521 | return 0; | |
522 | ||
523 | free_oldbuf: | |
524 | kfree(oldbuf); | |
525 | return ret; | |
526 | } | |
527 | ||
d26c3321 WL |
528 | /** |
529 | * psz_recovery() - recover data from storage | |
530 | * @cxt: the context of pstore/zone | |
531 | * | |
532 | * recovery means reading data back from storage after rebooting | |
533 | * | |
534 | * Return: 0 on success, others on failure. | |
535 | */ | |
536 | static inline int psz_recovery(struct psz_context *cxt) | |
537 | { | |
538 | int ret; | |
539 | ||
540 | if (atomic_read(&cxt->recovered)) | |
541 | return 0; | |
542 | ||
543 | ret = psz_kmsg_recover(cxt); | |
0dc06826 WL |
544 | if (ret) |
545 | goto out; | |
d26c3321 | 546 | |
0dc06826 WL |
547 | ret = psz_recover_zone(cxt, cxt->ppsz); |
548 | ||
549 | out: | |
d26c3321 WL |
550 | if (unlikely(ret)) |
551 | pr_err("recover failed\n"); | |
552 | else { | |
553 | pr_debug("recover end!\n"); | |
554 | atomic_set(&cxt->recovered, 1); | |
555 | } | |
556 | return ret; | |
557 | } | |
558 | ||
559 | static int psz_pstore_open(struct pstore_info *psi) | |
560 | { | |
561 | struct psz_context *cxt = psi->data; | |
562 | ||
563 | cxt->kmsg_read_cnt = 0; | |
0dc06826 | 564 | cxt->pmsg_read_cnt = 0; |
d26c3321 WL |
565 | return 0; |
566 | } | |
567 | ||
0dc06826 WL |
568 | static inline bool psz_old_ok(struct pstore_zone *zone) |
569 | { | |
570 | if (zone && zone->oldbuf && atomic_read(&zone->oldbuf->datalen)) | |
571 | return true; | |
572 | return false; | |
573 | } | |
574 | ||
d26c3321 WL |
575 | static inline bool psz_ok(struct pstore_zone *zone) |
576 | { | |
577 | if (zone && zone->buffer && buffer_datalen(zone)) | |
578 | return true; | |
579 | return false; | |
580 | } | |
581 | ||
582 | static inline int psz_kmsg_erase(struct psz_context *cxt, | |
583 | struct pstore_zone *zone, struct pstore_record *record) | |
584 | { | |
585 | struct psz_buffer *buffer = zone->buffer; | |
586 | struct psz_kmsg_header *hdr = | |
587 | (struct psz_kmsg_header *)buffer->data; | |
588 | ||
589 | if (unlikely(!psz_ok(zone))) | |
590 | return 0; | |
591 | /* this zone is already updated, no need to erase */ | |
592 | if (record->count != hdr->counter) | |
593 | return 0; | |
594 | ||
595 | atomic_set(&zone->buffer->datalen, 0); | |
596 | return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); | |
597 | } | |
598 | ||
0dc06826 WL |
599 | static inline int psz_record_erase(struct psz_context *cxt, |
600 | struct pstore_zone *zone) | |
601 | { | |
602 | if (unlikely(!psz_old_ok(zone))) | |
603 | return 0; | |
604 | ||
605 | kfree(zone->oldbuf); | |
606 | zone->oldbuf = NULL; | |
607 | /* | |
608 | * if there are new data in zone buffer, that means the old data | |
609 | * are already invalid. It is no need to flush 0 (erase) to | |
610 | * block device. | |
611 | */ | |
612 | if (!buffer_datalen(zone)) | |
613 | return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); | |
614 | psz_flush_dirty_zone(zone); | |
615 | return 0; | |
616 | } | |
617 | ||
d26c3321 WL |
618 | static int psz_pstore_erase(struct pstore_record *record) |
619 | { | |
620 | struct psz_context *cxt = record->psi->data; | |
621 | ||
622 | switch (record->type) { | |
623 | case PSTORE_TYPE_DMESG: | |
624 | if (record->id >= cxt->kmsg_max_cnt) | |
625 | return -EINVAL; | |
626 | return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record); | |
0dc06826 WL |
627 | case PSTORE_TYPE_PMSG: |
628 | return psz_record_erase(cxt, cxt->ppsz); | |
d26c3321 WL |
629 | default: |
630 | return -EINVAL; | |
631 | } | |
632 | } | |
633 | ||
634 | static void psz_write_kmsg_hdr(struct pstore_zone *zone, | |
635 | struct pstore_record *record) | |
636 | { | |
637 | struct psz_context *cxt = record->psi->data; | |
638 | struct psz_buffer *buffer = zone->buffer; | |
639 | struct psz_kmsg_header *hdr = | |
640 | (struct psz_kmsg_header *)buffer->data; | |
641 | ||
642 | hdr->magic = PSTORE_KMSG_HEADER_MAGIC; | |
643 | hdr->compressed = record->compressed; | |
644 | hdr->time.tv_sec = record->time.tv_sec; | |
645 | hdr->time.tv_nsec = record->time.tv_nsec; | |
646 | hdr->reason = record->reason; | |
647 | if (hdr->reason == KMSG_DUMP_OOPS) | |
648 | hdr->counter = ++cxt->oops_counter; | |
649 | else if (hdr->reason == KMSG_DUMP_PANIC) | |
650 | hdr->counter = ++cxt->panic_counter; | |
651 | else | |
652 | hdr->counter = 0; | |
653 | } | |
654 | ||
655 | static inline int notrace psz_kmsg_write_record(struct psz_context *cxt, | |
656 | struct pstore_record *record) | |
657 | { | |
658 | size_t size, hlen; | |
659 | struct pstore_zone *zone; | |
660 | unsigned int zonenum; | |
661 | ||
662 | zonenum = cxt->kmsg_write_cnt; | |
663 | zone = cxt->kpszs[zonenum]; | |
664 | if (unlikely(!zone)) | |
665 | return -ENOSPC; | |
666 | cxt->kmsg_write_cnt = (zonenum + 1) % cxt->kmsg_max_cnt; | |
667 | ||
668 | pr_debug("write %s to zone id %d\n", zone->name, zonenum); | |
669 | psz_write_kmsg_hdr(zone, record); | |
670 | hlen = sizeof(struct psz_kmsg_header); | |
671 | size = min_t(size_t, record->size, zone->buffer_size - hlen); | |
672 | return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); | |
673 | } | |
674 | ||
675 | static int notrace psz_kmsg_write(struct psz_context *cxt, | |
676 | struct pstore_record *record) | |
677 | { | |
678 | int ret; | |
679 | ||
680 | /* | |
681 | * Explicitly only take the first part of any new crash. | |
682 | * If our buffer is larger than kmsg_bytes, this can never happen, | |
683 | * and if our buffer is smaller than kmsg_bytes, we don't want the | |
684 | * report split across multiple records. | |
685 | */ | |
686 | if (record->part != 1) | |
687 | return -ENOSPC; | |
688 | ||
689 | if (!cxt->kpszs) | |
690 | return -ENOSPC; | |
691 | ||
692 | ret = psz_kmsg_write_record(cxt, record); | |
693 | if (!ret) { | |
694 | pr_debug("try to flush other dirty zones\n"); | |
695 | psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt); | |
696 | } | |
697 | ||
698 | /* always return 0 as we had handled it on buffer */ | |
699 | return 0; | |
700 | } | |
701 | ||
0dc06826 WL |
702 | static int notrace psz_record_write(struct pstore_zone *zone, |
703 | struct pstore_record *record) | |
704 | { | |
705 | size_t start, rem; | |
706 | bool is_full_data = false; | |
707 | char *buf; | |
708 | int cnt; | |
709 | ||
710 | if (!zone || !record) | |
711 | return -ENOSPC; | |
712 | ||
713 | if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size) | |
714 | is_full_data = true; | |
715 | ||
716 | cnt = record->size; | |
717 | buf = record->buf; | |
718 | if (unlikely(cnt > zone->buffer_size)) { | |
719 | buf += cnt - zone->buffer_size; | |
720 | cnt = zone->buffer_size; | |
721 | } | |
722 | ||
723 | start = buffer_start(zone); | |
724 | rem = zone->buffer_size - start; | |
725 | if (unlikely(rem < cnt)) { | |
726 | psz_zone_write(zone, FLUSH_PART, buf, rem, start); | |
727 | buf += rem; | |
728 | cnt -= rem; | |
729 | start = 0; | |
730 | is_full_data = true; | |
731 | } | |
732 | ||
733 | atomic_set(&zone->buffer->start, cnt + start); | |
734 | psz_zone_write(zone, FLUSH_PART, buf, cnt, start); | |
735 | ||
736 | /** | |
737 | * psz_zone_write will set datalen as start + cnt. | |
738 | * It work if actual data length lesser than buffer size. | |
739 | * If data length greater than buffer size, pmsg will rewrite to | |
740 | * beginning of zone, which make buffer->datalen wrongly. | |
741 | * So we should reset datalen as buffer size once actual data length | |
742 | * greater than buffer size. | |
743 | */ | |
744 | if (is_full_data) { | |
745 | atomic_set(&zone->buffer->datalen, zone->buffer_size); | |
746 | psz_zone_write(zone, FLUSH_META, NULL, 0, 0); | |
747 | } | |
748 | return 0; | |
749 | } | |
750 | ||
d26c3321 WL |
751 | static int notrace psz_pstore_write(struct pstore_record *record) |
752 | { | |
753 | struct psz_context *cxt = record->psi->data; | |
754 | ||
755 | if (record->type == PSTORE_TYPE_DMESG && | |
756 | record->reason == KMSG_DUMP_PANIC) | |
757 | atomic_set(&cxt->on_panic, 1); | |
758 | ||
759 | switch (record->type) { | |
760 | case PSTORE_TYPE_DMESG: | |
761 | return psz_kmsg_write(cxt, record); | |
0dc06826 WL |
762 | case PSTORE_TYPE_PMSG: |
763 | return psz_record_write(cxt->ppsz, record); | |
d26c3321 WL |
764 | default: |
765 | return -EINVAL; | |
766 | } | |
767 | } | |
768 | ||
769 | static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) | |
770 | { | |
771 | struct pstore_zone *zone = NULL; | |
772 | ||
773 | while (cxt->kmsg_read_cnt < cxt->kmsg_max_cnt) { | |
774 | zone = cxt->kpszs[cxt->kmsg_read_cnt++]; | |
775 | if (psz_ok(zone)) | |
776 | return zone; | |
777 | } | |
778 | ||
0dc06826 WL |
779 | if (cxt->pmsg_read_cnt == 0) { |
780 | cxt->pmsg_read_cnt++; | |
781 | zone = cxt->ppsz; | |
782 | if (psz_old_ok(zone)) | |
783 | return zone; | |
784 | } | |
785 | ||
d26c3321 WL |
786 | return NULL; |
787 | } | |
788 | ||
789 | static int psz_kmsg_read_hdr(struct pstore_zone *zone, | |
790 | struct pstore_record *record) | |
791 | { | |
792 | struct psz_buffer *buffer = zone->buffer; | |
793 | struct psz_kmsg_header *hdr = | |
794 | (struct psz_kmsg_header *)buffer->data; | |
795 | ||
796 | if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) | |
797 | return -EINVAL; | |
798 | record->compressed = hdr->compressed; | |
799 | record->time.tv_sec = hdr->time.tv_sec; | |
800 | record->time.tv_nsec = hdr->time.tv_nsec; | |
801 | record->reason = hdr->reason; | |
802 | record->count = hdr->counter; | |
803 | return 0; | |
804 | } | |
805 | ||
806 | static ssize_t psz_kmsg_read(struct pstore_zone *zone, | |
807 | struct pstore_record *record) | |
808 | { | |
809 | ssize_t size, hlen = 0; | |
810 | ||
811 | size = buffer_datalen(zone); | |
812 | /* Clear and skip this kmsg dump record if it has no valid header */ | |
813 | if (psz_kmsg_read_hdr(zone, record)) { | |
814 | atomic_set(&zone->buffer->datalen, 0); | |
815 | atomic_set(&zone->dirty, 0); | |
816 | return -ENOMSG; | |
817 | } | |
818 | size -= sizeof(struct psz_kmsg_header); | |
819 | ||
820 | if (!record->compressed) { | |
821 | char *buf = kasprintf(GFP_KERNEL, "%s: Total %d times\n", | |
822 | kmsg_dump_reason_str(record->reason), | |
823 | record->count); | |
824 | hlen = strlen(buf); | |
825 | record->buf = krealloc(buf, hlen + size, GFP_KERNEL); | |
826 | if (!record->buf) { | |
827 | kfree(buf); | |
828 | return -ENOMEM; | |
829 | } | |
830 | } else { | |
831 | record->buf = kmalloc(size, GFP_KERNEL); | |
832 | if (!record->buf) | |
833 | return -ENOMEM; | |
834 | } | |
835 | ||
0dc06826 | 836 | size = psz_zone_read_buffer(zone, record->buf + hlen, size, |
d26c3321 WL |
837 | sizeof(struct psz_kmsg_header)); |
838 | if (unlikely(size < 0)) { | |
839 | kfree(record->buf); | |
840 | return -ENOMSG; | |
841 | } | |
842 | ||
843 | return size + hlen; | |
844 | } | |
845 | ||
0dc06826 WL |
846 | static ssize_t psz_record_read(struct pstore_zone *zone, |
847 | struct pstore_record *record) | |
848 | { | |
849 | size_t len; | |
850 | struct psz_buffer *buf; | |
851 | ||
852 | if (!zone || !record) | |
853 | return -ENOSPC; | |
854 | ||
855 | buf = (struct psz_buffer *)zone->oldbuf; | |
856 | if (!buf) | |
857 | return -ENOMSG; | |
858 | ||
859 | len = atomic_read(&buf->datalen); | |
860 | record->buf = kmalloc(len, GFP_KERNEL); | |
861 | if (!record->buf) | |
862 | return -ENOMEM; | |
863 | ||
864 | if (unlikely(psz_zone_read_oldbuf(zone, record->buf, len, 0))) { | |
865 | kfree(record->buf); | |
866 | return -ENOMSG; | |
867 | } | |
868 | ||
869 | return len; | |
870 | } | |
871 | ||
d26c3321 WL |
872 | static ssize_t psz_pstore_read(struct pstore_record *record) |
873 | { | |
874 | struct psz_context *cxt = record->psi->data; | |
875 | ssize_t (*readop)(struct pstore_zone *zone, | |
876 | struct pstore_record *record); | |
877 | struct pstore_zone *zone; | |
878 | ssize_t ret; | |
879 | ||
880 | /* before read, we must recover from storage */ | |
881 | ret = psz_recovery(cxt); | |
882 | if (ret) | |
883 | return ret; | |
884 | ||
885 | next_zone: | |
886 | zone = psz_read_next_zone(cxt); | |
887 | if (!zone) | |
888 | return 0; | |
889 | ||
890 | record->type = zone->type; | |
891 | switch (record->type) { | |
892 | case PSTORE_TYPE_DMESG: | |
893 | readop = psz_kmsg_read; | |
894 | record->id = cxt->kmsg_read_cnt - 1; | |
895 | break; | |
0dc06826 WL |
896 | case PSTORE_TYPE_PMSG: |
897 | readop = psz_record_read; | |
898 | break; | |
d26c3321 WL |
899 | default: |
900 | goto next_zone; | |
901 | } | |
902 | ||
903 | ret = readop(zone, record); | |
904 | if (ret == -ENOMSG) | |
905 | goto next_zone; | |
906 | return ret; | |
907 | } | |
908 | ||
909 | static struct psz_context pstore_zone_cxt = { | |
910 | .pstore_zone_info_lock = | |
911 | __MUTEX_INITIALIZER(pstore_zone_cxt.pstore_zone_info_lock), | |
912 | .recovered = ATOMIC_INIT(0), | |
913 | .on_panic = ATOMIC_INIT(0), | |
914 | .pstore = { | |
915 | .owner = THIS_MODULE, | |
916 | .open = psz_pstore_open, | |
917 | .read = psz_pstore_read, | |
918 | .write = psz_pstore_write, | |
919 | .erase = psz_pstore_erase, | |
920 | }, | |
921 | }; | |
922 | ||
923 | static void psz_free_zone(struct pstore_zone **pszone) | |
924 | { | |
925 | struct pstore_zone *zone = *pszone; | |
926 | ||
927 | if (!zone) | |
928 | return; | |
929 | ||
930 | kfree(zone->buffer); | |
931 | kfree(zone); | |
932 | *pszone = NULL; | |
933 | } | |
934 | ||
935 | static void psz_free_zones(struct pstore_zone ***pszones, unsigned int *cnt) | |
936 | { | |
937 | struct pstore_zone **zones = *pszones; | |
938 | ||
939 | if (!zones) | |
940 | return; | |
941 | ||
942 | while (*cnt > 0) { | |
943 | (*cnt)--; | |
944 | psz_free_zone(&(zones[*cnt])); | |
945 | } | |
946 | kfree(zones); | |
947 | *pszones = NULL; | |
948 | } | |
949 | ||
950 | static void psz_free_all_zones(struct psz_context *cxt) | |
951 | { | |
952 | if (cxt->kpszs) | |
953 | psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt); | |
0dc06826 WL |
954 | if (cxt->ppsz) |
955 | psz_free_zone(&cxt->ppsz); | |
d26c3321 WL |
956 | } |
957 | ||
958 | static struct pstore_zone *psz_init_zone(enum pstore_type_id type, | |
959 | loff_t *off, size_t size) | |
960 | { | |
961 | struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; | |
962 | struct pstore_zone *zone; | |
963 | const char *name = pstore_type_to_name(type); | |
964 | ||
965 | if (!size) | |
966 | return NULL; | |
967 | ||
968 | if (*off + size > info->total_size) { | |
969 | pr_err("no room for %s (0x%zx@0x%llx over 0x%lx)\n", | |
970 | name, size, *off, info->total_size); | |
971 | return ERR_PTR(-ENOMEM); | |
972 | } | |
973 | ||
974 | zone = kzalloc(sizeof(struct pstore_zone), GFP_KERNEL); | |
975 | if (!zone) | |
976 | return ERR_PTR(-ENOMEM); | |
977 | ||
978 | zone->buffer = kmalloc(size, GFP_KERNEL); | |
979 | if (!zone->buffer) { | |
980 | kfree(zone); | |
981 | return ERR_PTR(-ENOMEM); | |
982 | } | |
983 | memset(zone->buffer, 0xFF, size); | |
984 | zone->off = *off; | |
985 | zone->name = name; | |
986 | zone->type = type; | |
987 | zone->buffer_size = size - sizeof(struct psz_buffer); | |
988 | zone->buffer->sig = type ^ PSZ_SIG; | |
0dc06826 | 989 | zone->oldbuf = NULL; |
d26c3321 WL |
990 | atomic_set(&zone->dirty, 0); |
991 | atomic_set(&zone->buffer->datalen, 0); | |
0dc06826 | 992 | atomic_set(&zone->buffer->start, 0); |
d26c3321 WL |
993 | |
994 | *off += size; | |
995 | ||
996 | pr_debug("pszone %s: off 0x%llx, %zu header, %zu data\n", zone->name, | |
997 | zone->off, sizeof(*zone->buffer), zone->buffer_size); | |
998 | return zone; | |
999 | } | |
1000 | ||
1001 | static struct pstore_zone **psz_init_zones(enum pstore_type_id type, | |
1002 | loff_t *off, size_t total_size, ssize_t record_size, | |
1003 | unsigned int *cnt) | |
1004 | { | |
1005 | struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; | |
1006 | struct pstore_zone **zones, *zone; | |
1007 | const char *name = pstore_type_to_name(type); | |
1008 | int c, i; | |
1009 | ||
1010 | *cnt = 0; | |
1011 | if (!total_size || !record_size) | |
1012 | return NULL; | |
1013 | ||
1014 | if (*off + total_size > info->total_size) { | |
1015 | pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n", | |
1016 | name, total_size, *off, info->total_size); | |
1017 | return ERR_PTR(-ENOMEM); | |
1018 | } | |
1019 | ||
1020 | c = total_size / record_size; | |
1021 | zones = kcalloc(c, sizeof(*zones), GFP_KERNEL); | |
1022 | if (!zones) { | |
1023 | pr_err("allocate for zones %s failed\n", name); | |
1024 | return ERR_PTR(-ENOMEM); | |
1025 | } | |
1026 | memset(zones, 0, c * sizeof(*zones)); | |
1027 | ||
1028 | for (i = 0; i < c; i++) { | |
1029 | zone = psz_init_zone(type, off, record_size); | |
1030 | if (!zone || IS_ERR(zone)) { | |
1031 | pr_err("initialize zones %s failed\n", name); | |
1032 | psz_free_zones(&zones, &i); | |
1033 | return (void *)zone; | |
1034 | } | |
1035 | zones[i] = zone; | |
1036 | } | |
1037 | ||
1038 | *cnt = c; | |
1039 | return zones; | |
1040 | } | |
1041 | ||
1042 | static int psz_alloc_zones(struct psz_context *cxt) | |
1043 | { | |
1044 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
1045 | loff_t off = 0; | |
1046 | int err; | |
0dc06826 WL |
1047 | size_t off_size = 0; |
1048 | ||
1049 | off_size += info->pmsg_size; | |
1050 | cxt->ppsz = psz_init_zone(PSTORE_TYPE_PMSG, &off, info->pmsg_size); | |
1051 | if (IS_ERR(cxt->ppsz)) { | |
1052 | err = PTR_ERR(cxt->ppsz); | |
1053 | cxt->ppsz = NULL; | |
1054 | goto free_out; | |
1055 | } | |
d26c3321 | 1056 | |
0dc06826 WL |
1057 | cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, |
1058 | info->total_size - off_size, | |
d26c3321 WL |
1059 | info->kmsg_size, &cxt->kmsg_max_cnt); |
1060 | if (IS_ERR(cxt->kpszs)) { | |
1061 | err = PTR_ERR(cxt->kpszs); | |
1062 | cxt->kpszs = NULL; | |
0dc06826 | 1063 | goto free_out; |
d26c3321 WL |
1064 | } |
1065 | ||
1066 | return 0; | |
0dc06826 WL |
1067 | free_out: |
1068 | psz_free_all_zones(cxt); | |
d26c3321 WL |
1069 | return err; |
1070 | } | |
1071 | ||
1072 | /** | |
1073 | * register_pstore_zone() - register to pstore/zone | |
1074 | * | |
1075 | * @info: back-end driver information. See &struct pstore_zone_info. | |
1076 | * | |
1077 | * Only one back-end at one time. | |
1078 | * | |
1079 | * Return: 0 on success, others on failure. | |
1080 | */ | |
1081 | int register_pstore_zone(struct pstore_zone_info *info) | |
1082 | { | |
1083 | int err = -EINVAL; | |
1084 | struct psz_context *cxt = &pstore_zone_cxt; | |
1085 | ||
1086 | if (info->total_size < 4096) { | |
1087 | pr_warn("total_size must be >= 4096\n"); | |
1088 | return -EINVAL; | |
1089 | } | |
1090 | ||
0dc06826 | 1091 | if (!info->kmsg_size && !info->pmsg_size) { |
d26c3321 WL |
1092 | pr_warn("at least one record size must be non-zero\n"); |
1093 | return -EINVAL; | |
1094 | } | |
1095 | ||
1096 | if (!info->name || !info->name[0]) | |
1097 | return -EINVAL; | |
1098 | ||
1099 | #define check_size(name, size) { \ | |
1100 | if (info->name > 0 && info->name < (size)) { \ | |
1101 | pr_err(#name " must be over %d\n", (size)); \ | |
1102 | return -EINVAL; \ | |
1103 | } \ | |
1104 | if (info->name & (size - 1)) { \ | |
1105 | pr_err(#name " must be a multiple of %d\n", \ | |
1106 | (size)); \ | |
1107 | return -EINVAL; \ | |
1108 | } \ | |
1109 | } | |
1110 | ||
1111 | check_size(total_size, 4096); | |
1112 | check_size(kmsg_size, SECTOR_SIZE); | |
0dc06826 | 1113 | check_size(pmsg_size, SECTOR_SIZE); |
d26c3321 WL |
1114 | |
1115 | #undef check_size | |
1116 | ||
1117 | /* | |
1118 | * the @read and @write must be applied. | |
1119 | * if no @read, pstore may mount failed. | |
1120 | * if no @write, pstore do not support to remove record file. | |
1121 | */ | |
1122 | if (!info->read || !info->write) { | |
1123 | pr_err("no valid general read/write interface\n"); | |
1124 | return -EINVAL; | |
1125 | } | |
1126 | ||
1127 | mutex_lock(&cxt->pstore_zone_info_lock); | |
1128 | if (cxt->pstore_zone_info) { | |
1129 | pr_warn("'%s' already loaded: ignoring '%s'\n", | |
1130 | cxt->pstore_zone_info->name, info->name); | |
1131 | mutex_unlock(&cxt->pstore_zone_info_lock); | |
1132 | return -EBUSY; | |
1133 | } | |
1134 | cxt->pstore_zone_info = info; | |
1135 | ||
1136 | pr_debug("register %s with properties:\n", info->name); | |
1137 | pr_debug("\ttotal size : %ld Bytes\n", info->total_size); | |
1138 | pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size); | |
0dc06826 | 1139 | pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size); |
d26c3321 WL |
1140 | |
1141 | err = psz_alloc_zones(cxt); | |
1142 | if (err) { | |
1143 | pr_err("alloc zones failed\n"); | |
1144 | goto fail_out; | |
1145 | } | |
1146 | ||
1147 | if (info->kmsg_size) { | |
1148 | cxt->pstore.bufsize = cxt->kpszs[0]->buffer_size - | |
1149 | sizeof(struct psz_kmsg_header); | |
1150 | cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL); | |
1151 | if (!cxt->pstore.buf) { | |
1152 | err = -ENOMEM; | |
1153 | goto fail_free; | |
1154 | } | |
1155 | } | |
1156 | cxt->pstore.data = cxt; | |
1157 | ||
1158 | pr_info("registered %s as backend for", info->name); | |
1159 | cxt->pstore.max_reason = info->max_reason; | |
1160 | cxt->pstore.name = info->name; | |
1161 | if (info->kmsg_size) { | |
1162 | cxt->pstore.flags |= PSTORE_FLAGS_DMESG; | |
1163 | pr_cont(" kmsg(%s", | |
1164 | kmsg_dump_reason_str(cxt->pstore.max_reason)); | |
1165 | if (cxt->pstore_zone_info->panic_write) | |
1166 | pr_cont(",panic_write"); | |
1167 | pr_cont(")"); | |
1168 | } | |
0dc06826 WL |
1169 | if (info->pmsg_size) { |
1170 | cxt->pstore.flags |= PSTORE_FLAGS_PMSG; | |
1171 | pr_cont(" pmsg"); | |
1172 | } | |
d26c3321 WL |
1173 | pr_cont("\n"); |
1174 | ||
1175 | err = pstore_register(&cxt->pstore); | |
1176 | if (err) { | |
1177 | pr_err("registering with pstore failed\n"); | |
1178 | goto fail_free; | |
1179 | } | |
1180 | mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock); | |
1181 | ||
1182 | return 0; | |
1183 | ||
1184 | fail_free: | |
1185 | kfree(cxt->pstore.buf); | |
1186 | cxt->pstore.buf = NULL; | |
1187 | cxt->pstore.bufsize = 0; | |
1188 | psz_free_all_zones(cxt); | |
1189 | fail_out: | |
1190 | pstore_zone_cxt.pstore_zone_info = NULL; | |
1191 | mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock); | |
1192 | return err; | |
1193 | } | |
1194 | EXPORT_SYMBOL_GPL(register_pstore_zone); | |
1195 | ||
1196 | /** | |
1197 | * unregister_pstore_zone() - unregister to pstore/zone | |
1198 | * | |
1199 | * @info: back-end driver information. See struct pstore_zone_info. | |
1200 | */ | |
1201 | void unregister_pstore_zone(struct pstore_zone_info *info) | |
1202 | { | |
1203 | struct psz_context *cxt = &pstore_zone_cxt; | |
1204 | ||
1205 | mutex_lock(&cxt->pstore_zone_info_lock); | |
1206 | if (!cxt->pstore_zone_info) { | |
1207 | mutex_unlock(&cxt->pstore_zone_info_lock); | |
1208 | return; | |
1209 | } | |
1210 | ||
1211 | /* Stop incoming writes from pstore. */ | |
1212 | pstore_unregister(&cxt->pstore); | |
1213 | ||
1214 | /* Clean up allocations. */ | |
1215 | kfree(cxt->pstore.buf); | |
1216 | cxt->pstore.buf = NULL; | |
1217 | cxt->pstore.bufsize = 0; | |
1218 | cxt->pstore_zone_info = NULL; | |
1219 | ||
1220 | psz_free_all_zones(cxt); | |
1221 | ||
1222 | /* Clear counters and zone state. */ | |
1223 | cxt->oops_counter = 0; | |
1224 | cxt->panic_counter = 0; | |
1225 | atomic_set(&cxt->recovered, 0); | |
1226 | atomic_set(&cxt->on_panic, 0); | |
1227 | ||
1228 | mutex_unlock(&cxt->pstore_zone_info_lock); | |
1229 | } | |
1230 | EXPORT_SYMBOL_GPL(unregister_pstore_zone); | |
1231 | ||
1232 | MODULE_LICENSE("GPL"); | |
1233 | MODULE_AUTHOR("WeiXiong Liao <liaoweixiong@allwinnertech.com>"); | |
1234 | MODULE_AUTHOR("Kees Cook <keescook@chromium.org>"); | |
1235 | MODULE_DESCRIPTION("Storage Manager for pstore/blk"); |